The present invention relates to a method of feeding and folding sheet material on a packing machine.
In particular, the present invention relates to a method of feeding and folding, on the wrapping line of a packing machine, sheet material for the formation of strengthening collars for flip-top cigarette packets and, if required, also coupons inserted inside the packets.
Flip-top cigarette packets usually comprise a strengthening element or collar over the inside foil wrapping and extending along the edges of the opening closed by the lid.
Known flip-top packing machines employ a collar feeding device connected to a wheel on the wrapping line of the machine, which wheel usually presents seats for receiving respective groups of foil-wrapped cigarettes as well as respective collars.
On known packing machines, the collars are usually formed by folding, substantially in the form of a U, flat portions of sheet material as these are fed along a line to the packing machine. Once formed, the collars are inserted inside respective seats on the wrapping line wheel prior to inserting the foil-wrapped cigarettes. The above method obviously involves the use of numerous relatively complex, high-cost mechanical devices, such as folding elements on the outside of the wrapping wheel, and gripping elements for each seat on the wrapping line wheel for retaining the collar in such a position inside the wheel as to enable subsequent insertion of the foil-wrapped cigarettes.